1. Field of the Invention
The present invention relates to a bag with a gas filling compartment made of an inner bag and an outer bag having a gas filled in between the inner bag and the outer bag to protect the contents packaged inside the inner bag from shock or the like and also relates to a manufacturing method of such a bag and further to a gas filling method in such a bag and a packaging method for such a bag.
2. Description of the Related Art
Bag with a gas filling compartment (or with an air bag) comprising an outer bag and an inner bag that is provided inside the outer bag, made so that a gas is filled in between the inner bag and the outer bag, are commonly known and disclosed in, for instance, Japanese Utility Model Application Laid-Open (Kokai) Nos. 64-2745 and 8-1398; Japanese Patent Application Laid-Open (Kokai) Nos. 64-84869, 2-98563 and 9-132213; and Japanese Patent Nos. 2800034 and 3015323
However, conventional bag with a gas filling compartment does not have a structure suitable for automating the process of sealing gas into the bas filling spaces or for automating the entire packaging process including such a gas sealing process, and the gas sealing process disclosed in, for instance, Japanese Utility Model Application Laid-Open (Kokai) 8-1398 is also not suitable for being automated.